Greetings,

We have a small group of users that just started getting this error message:

piwigo encountered an irrecoverable error ./_data/templates_c no write access #1 mkgetdir f:\inetpub\wwwroot\secure\piwigo\include\template.class.php(101) #2 template::__construct f:\inetpub\wwwroot\secure\piwigo\include\common.inc.php(238) #3 include_once f:\inetpub\wwwroot\secure\piwigo\index.php(11)

Piwigo 13.0.0 Check for upgrade
Installed on 7 September 2021, 1 year 6 months 3 weeks ago
Operating system: WINNT
PHP: 7.4.13 (Show info) [2023-03-29 15:10:06]
MySQL: 5.5.5-10.5.8-MariaDB [2023-03-29 15:10:06]
Graphics Library: GD bundled (2.1.0 compatible)
Cache size N/A   never calculated Refresh

Our Piwigo is hosted on an intranet page, not accessible to the public. 

I inherited this Piwigo from our last admin that retired and have little to no experience with it as a whole.  I've searched a bit on this error but can't find many solutions.  Any tips or advice would be amazing.